1. Field of the Invention
This invention relates generally to restorative dentistry, and is more particularly concerned with an adjustable fixture to be attached to a dental implant.
2. Discussion of the Prior Art
It is well known in the art as a means to replace a missing tooth, or some missing teeth, to place an implant into the bone, extending close to the gum line. A prosthesis is then attached to the implant, so the prosthesis is substantially permanent. When the implant is installed along a line coaxial with the centerline of the intended prosthesis, a simple fixture provides for attachment of the prosthesis to the implant.
When an implant is installed, one must drill a hole into the bone, the implant then being screwed, or driven, into the hole. Due to the anatomy of the body, however, one frequently cannot drill the ideal hole to receive the implant. For example, the ideal hole for the implant may sometimes protrude through the surface of the bone. Similarly, the ideal hole may extend into one of the facial sinuses. In each case, the hole for the implant must be angled to be sure the entire implant is within the bone.
Though an angled hole for the implant solves the problem of perforating the bone surface, it creates another problem in that the prosthesis to be attached to the implant will also be angled, which will be unacceptable. As a result, a more complex fixture is required in order to align the prosthesis properly in the dental arch in spite of one or more angled implants.
There is a very elaborate fixture system made by Universal Implant Systems, Inc., in Washington, D.C., but this system is quite complex, including perhaps six separate pieces for a single tooth. Even so, the final step is to make a custom casting for use with the system. Also, if the implant is angled, the correction requires selection of one of a plurality of angled pieces in an effort find a complementarily angled piece so the prosthesis will be straight. The dentist is therefore required to have a sufficient inventory to include all the pieces that may be needed for any given patient.